1. Field of the Invention
This invention relates generally to methods and apparatus for covering and thereby protecting the pilings of piers, wharfs, or other structures extending from a waterfront or free-standing in a body of water.
2. Description of the Prior Art
Piers, wharfs, quays and free standing structures utilized for the docking of vessels or as platforms in the sea are commonly supported by wooden, concrete or metal piles which extend longitudinally from immediately underneath the pier platform, downwardly through the water to the earth's surface therebelow. Immersion of the lower portion of a pile in seawater and exposure of the remaining portion of a pile to an inhospitable sea environment substantially diminishes a pile's useful life. Unprotected piles, in addition to being exposed to water and the elements, are susceptible to attack by marine organisms. Various worms, snails, bacteria and marine life act to destroy the integrity of wood or to corrode and destroy the metal. Further, the piles are often rammed by boat fenders, breaking the piles. Abrasion by shifting and washing sand is especially a problem for metal and concrete piles. Ultimately, the wood, concrete and metal are destroyed and the piling must be replaced. This is a very expensive and labor intensive process. Therefore, various protective measures have been employed to forstall the deterioration of piling.
Various devices and methods have been utilized in the past to protect piles. One of the oldest methods of protecting piles is to soak wooden piles with tar. However, the tar soon wears off. More recently, coverings such as zippered plastic covers, plastic covers connected by tongue and groove, plastic covers which are overlapped and spiked, and fiberglass or plastic flanged and bolted covers has been used on metal, concrete and wooden piles. These cover devices have also proven unsatisfactory. Most importantly, most pile coverings do not provide a good seal and do not prevent water, marine life and bacteria from entering the wood. While tar and mastics have been applied beneath the covers, the seawater and animal life still can penetrate the plastic cover. Ultimately, the wood, concrete and metal are penetrated and destroyed because the cover has holes punched in it by spikes or gaps are present in the flanges or cover ends.
To illustrate, one protective covering and method employed in the prior art utilizes a fiberglass cover. The fiberglass cover employed by this system is an axially flanged fiberglass split-sleeve which is tightened around a pile by bolting the axial flange together. Prior to installation of the fiberglass cover, the pile is covered with a mastic and then spirally wrapped with a coated paper to seal the surface of the pile. The fiberglass cover itself does not seal the pile surface since the pre-formed fiberglass will not conform to surface imperfections and diameter changes which are present in all wooden piles, concrete piles and corroded metal piles. More mastics and caulks are applied about the cover in an attempt to further seal the pile from the water. However, the mastics and caulks wear and wash away and water and animal life attacks the pile beneath the cover.
A variation of the above method substitutes a plastic flanged split-sleeve cover in place of the fiberglass cover. A flanged cover of either fiberglass or plastic material must be custom sized to the particular metal or wooden pile to be covered or else the fit is particularly bad. Many piles are formed from tree trunks which are larger at one end causing even a custom sized cover to fit poorly. An additional problem with flanged covers is corrosion of the flanged connectors, which are usually nuts and bolts.
In addition to the naturally induced deterioration mentioned above, pile coverings are also damaged by vessels striking or abrading their sides during docking. This is especially true of fiberglass covers which are inherently brittle and subject to cracking upon impact. Although fiberglass and plastic are relatively easily patched above water, they are difficult to patch below water. Also, damage to the flange of a fiberglass or plastic cover requires a substantial amount of labor to rebuild the damaged portion of the flange.
All of the covering and mastic application methods are made more difficult by the fact that they must sometimes be performed in the water. Divers are expensive labor and the water environment makes many tasks, which would otherwise be simple, very difficult or impossible.